Manual stretcher

ABSTRACT

A manual stretcher includes a frame, a shaft, a ratchet, a claw, a joint and a crank. The frame includes two lateral plates, an intermediate plate interconnecting the lateral plates and a hole defined in each of the lateral plates. The frame can be attached to an external structure so that the manual stretcher can be retained in position in operation. The shaft includes a slot defined therein for receiving a portion of a strip of work to be stretched. The shaft is inserted through the holes. The ratchet is mounted on an end of the shaft. The claw is pivotally mounted on one of the lateral plates of the frame for engagement with the ratchet. The joint is mounted on another end of the shaft for engagement with the crank for rotation of the shaft. The shaft includes two halves. The ratchet includes two meniscus holes defined therein for receiving the halves of the shaft. The joint includes two meniscus recesses defined in an end thereof for receiving the halves of the shaft. Each of the halves of the shaft may include a stop formed on an end thereof for abutting the ratchet. Each of the halves of the shaft includes a hole defined in an end thereof. The joint include two opposite pin-receiving holes defined in a periphery thereof. A pin can be inserted in the holes defined in the halves of the shaft and the pin-receiving holes defined in the joint, thus securely mounting the joint on the halves of the shaft.

BACKGROUND OF THE INVENTION

[0001] 1. Field of Invention

[0002] The present invention is related to a manual stretcher.

[0003] 2. Related Prior Art

[0004] Referring to FIG. 5, a conventional manual stretcher includes aframe 1. The frame 1 includes a bracket (not numbered) formed thereon.The bracket can be securely attached to an external structure (notshown) so that the conventional manual stretcher can be retained inposition in operation. The frame 1 includes two lateral plates. A holeis defined in each of the lateral plates of the frame 1. A hollow shaft4 is inserted through the holes. A slot is defined in the hollow shaft 4for receiving a portion of a strip of work to be stretched (not shown).A ratchet 2 is soldered to an end of the hollow shaft 4 and a joint 3 issoldered to another end of the hollow shaft 4. A crank (not shown) canbe inserted in two holes defined in the joint 3. Thus, the crank can beoperated in order to rotate the hollow shaft 4 for stretching. Solderingcauses roughness on the hollow shaft 4. Roughness prevents smoothrotation of the hollow shaft 4 on the frame 1. Grinding is often takenso as to eliminate such roughness. Thus, the difficulty in finishing isincreased and time for fabrication is extended. Furthermore, solderinggive rise to flaws in structure and/or errors in dimension. In addition,points subject to soldering are vulnerable to concentration of stressand often become points of fracture.

[0005] The present invention is therefore intended to obviate or atleast alleviate the problems encountered in fabrication and use of theabove-mentioned conventional manual stretcher.

SUMMARY OF INVENTION

[0006] It is an objective of the present invention to provide a manualstretcher that can be fabricated precisely.

[0007] It is another objective of the present invention to provide a.manual stretcher that can be fabricated easily.

[0008] It is another objective of the present invention to provide a.manual stretcher that can be fabricated quickly.

[0009] It is another objective of the present invention to provide a.manual stretcher that can be fabricated easily.

[0010] It is another objective of the present invention to provide a.manual stretcher that is strong in structure.

[0011] In the present invention, a manual stretcher includes a frame, ashaft, a ratchet, a claw, a joint and a crank. The frame includes twolateral plates, an intermediate plate interconnecting the lateral platesand a hole defined in each of the lateral plates. The frame can beattached to an external structure so that the manual stretcher can beretained in position in operation. The shaft includes a slot definedtherein for receiving a portion of a strip of work to be stretched. Theshaft is inserted through the holes. The ratchet is mounted on an end ofthe shaft. The claw is pivotally mounted on one of the lateral plates ofthe frame for engagement with the ratchet. The joint is mounted onanother end of the shaft for engagement with the crank for rotation ofthe shaft.

[0012] The shaft may include two halves. The ratchet may include twomeniscus holes defined therein for receiving the halves of the shaft.The joint may include two meniscus recesses defined in an end thereoffor receiving the halves of the shaft.

[0013] Each of the halves of the shaft may include a stop formed on anend thereof for abutting the ratchet.

[0014] The stop formed on each of the halves of the shaft may be acurved ridge.

[0015] Each of the halves of the shaft may include a hole defined in anend thereof. The joint may include two opposite pin-receiving holesdefined in a periphery thereof. A pin can be inserted in the holesdefined in the halves of the shaft and the pin-receiving holes definedin the joint, thus securely mounting the joint on the halves of theshaft.

[0016] The joint may include a partition separating the meniscusrecesses from each other. A pin-receiving hole may be defined in thepartition of the joint.

[0017] The frame may include a bracket formed on the intermediate platefor attachment to the external structure.

[0018] The joint may include a number of crank-receiving holes definedin a periphery thereof for receiving the crank.

[0019] In an aspect of the present invention, the halves of the shaftare hollow. More particularly, each of the halves of the shaft is madeof a metal strip by folding.

[0020] In another aspect of the present invention, the halves of theshaft are solid.

[0021] Other objects, advantages, and novel features of the inventionwill become more apparent from the following detailed description whentaken in conjunction with the attached drawings.

BRIEF DESCRIPTION OF DRAWINGS

[0022] The present invention is described through detailed illustrationof embodiments referring to the attached drawings wherein:

[0023]FIG. 1 is a perspective view of a manual stretcher according tothe preferred embodiment of the present invention;

[0024]FIG. 2 is an exploded view of the manual stretcher shown in FIG.1;

[0025]FIG. 3 is a cross-sectional view taken along a line 3-3 in FIG. 1;

[0026]FIG. 4 is an exploded view of a manual stretcher according to asecond embodiment of the present invention; and

[0027]FIG. 5 is a cross-sectional view of a conventional manualstretcher.

DETAILED DESCRIPTION OF INVENTION

[0028] Referring to FIG. 1, according to the present invention, a manualstretcher includes a frame 10. The frame 10 includes two lateral platesand an intermediate plate interconnecting the lateral plates. The frame10 includes a bracket 11 formed on the intermediate plate thereof. Thebracket 11 can be securely attached to an external structure (not shown)so that the manual stretcher can be retained in position in operation. Ahole 12 is defined in each of the lateral plates of the frame 10. Ashaft 34 is inserted through the holes 12. A slot (not numbered) isdefined in the shaft 34 for receiving a portion of a strip of work to bestretched (not shown). A ratchet 20 is mounted on an end of the shaft 34and a joint 40 is mounted on another end of the shaft 34. A claw 13 ispivotally mounted on one of the lateral plates of the frame 10 forengagement with the ratchet 20. A crank (not shown) can be connectedwith the joint 40 and operated in order to rotate the shaft 34 forstretching.

[0029] Referring to FIGS. 2 and 3, the ratchet 20 includes a number ofteeth 21 formed along a periphery thereof and two meniscus holes 22defined therein. The meniscus holes 22 are separated from each other bymeans of a partition 23.

[0030] The shaft 34 includes two halves 30. Each of the halves 30 ismade of a metal strip by folding. Each of the halves 30 includes a hole31 defined in a first end thereof and a stop 32 in the form of a curvedridge formed on a second end thereof.

[0031] The joint 40 includes a number of crank-receiving holes 41defined in a periphery thereof, two meniscus recesses 42 defined in anend thereof. The meniscus recesses 42 are separated from each other bymeans of a partition 43. Two opposite pin-receiving holes 44 are definedin the periphery of the joint 40. Another pin-receiving hole 44 isdefined in the partition 43.

[0032] In assembly, each of the halves 30 is inserted in one of themeniscus holes 22. The halves 30 are inserted in the holes 12 until thestops 32 abut the ratchet 20 that in turn abuts one of the lateralplates of the frame 10. The first end of each of the halves 30 is beyondthe frame 10. A pin 45 is inserted in pin-receiving holes 44 and theholes 31, thus securely mounting the joint 40 on the halves 30.

[0033] In operation, a portion of a strip of work to be stretched (notshown) is positioned between the halves 30. The crank can be inserted intwo of the crank-receiving holes 41 and pivoted so as to rotate thehalves 30, thus stretching the strip of work.

[0034] Referring to FIG. 4, according to a second embodiment of thepresent invention, a manual stretcher includes a frame 10, a ratchet 20,a shaft 34′ and a joint 40. The second embodiment is identical to thefirst embodiment except for including a shaft 34′ instead of the shaft34. The shaft 34′ is identical to the shaft 34 except for including twosolid halves 30′ instead of two hollow halves 30.

[0035] The preferred embodiment of the present invention has beendescribed in detail for purposes of illustration. Those skilled in theart can derive a lot of variations from these embodiments after a studyof this patent specification. Therefore, these embodiments shall by nomeans limit the scope of the present invention. The scope of the presentinvention can only be defined in the claims attached to and taken as aportion of this patent specification.

1. A manual stretcher including: a frame (10) including two lateralplates, an intermediate plate connecting the lateral plates with eachother and a hole (12) defined in each of the lateral plates, wherein theframe (10) can be attached to an external structure so that the manualstretcher can be retained in position in operation; a shaft (34; 34′)including a slot defined therein for receiving a portion of a strip ofwork, wherein the shaft (34; 34′) is inserted through the holes (12); aratchet (20) mounted on an end of the shaft (34; 34′); a claw (13)pivotally mounted on one of the lateral plates of the frame (10) forengagement with the ratchet (20); and a joint (40) mounted on anotherend of the shaft (34; 34′) for engagement with a crank for rotation ofthe shaft (34; 34′).
 2. The manual stretcher according to claim 1wherein the shaft (34; 34′) includes two halves (30; 30′), wherein theratchet (20) includes two meniscus holes (22) defined therein forreceiving the halves (30; 30′) of the shaft (34; 34′), wherein the joint(40) includes two meniscus recesses (42) defined in an end thereof forreceiving the halves (30; 30′) of the shaft (34; 34′).
 3. The manualstretcher according to claim 2 wherein each of the halves (30; 30′) ofthe shaft (34; 34′) includes a stop (32) formed on an end thereof forabutting the ratchet (20).
 4. The manual stretcher according to claim 3wherein the stop (32) formed on each of the halves (30; 30′) of theshaft (34; 34′) is a curved ridge.
 5. The manual stretcher according toclaim 2 wherein each of the halves (30; 30′) of the shaft (34; 34′)includes a hole (31) defined in an end thereof, wherein the joint (40)includes two opposite pin-receiving holes (44) defined in a peripherythereof, wherein a pin (45) can be inserted in the holes (31) defined inthe halves (30; 30′) of the shaft (34; 34′) and the pin-receiving holes(44) defined in the joint (40), thus securely mounting the joint (40) onthe halves (30; 30′) of the shaft (34; 34′).
 6. The manual stretcheraccording to claim 5 wherein the joint (40) includes a partition (43)separating the meniscus recesses (42) from each other.
 7. The manualstretcher according to claim 6 wherein the partition (43) includes apin-receiving hole (44) defined therein.
 8. The according to claim 1wherein the frame 1 includes a bracket (11) formed on the intermediateplate for attachment to the external structure.
 9. The manual stretcheraccording to claim 1 wherein the joint (40) includes a number ofcrank-receiving holes (41) defined in a periphery thereof for receivingthe crank.
 10. The manual stretcher according to claim 2 wherein each ofthe halves (30) of the shaft (34) is hollow.
 11. The manual stretcheraccording to claim 10 wherein each of the halves (30) of the shaft (34)is made of a metal strip by folding.
 12. The manual stretcher accordingto claim 2 wherein each of the halves (30′) of the shaft (34′) is solid.